Anchor bolt assembly

Abstract

An anchor bolt assembly includes an anchor bolt and an expansion sleeve. The anchor bolt has a leading end and a trailing end and includes a cylindrically shaped body extending from the trailing end toward the leading end. A frusto-concial part extends from the leading end toward the trailing end. A reduced diameter part interconnects the adjacent ends of the body and the frusto-conical part. The reduced diameter part has a diameter smaller than that of the cylindrically shaped body and equal to the minimum diameter of the frusto-conical part. The expansion sleeve is fitted onto the reduced diameter part by deforming it inwardly into partial surface contact with the reduced diameter part. The expansion sleeve has at least one deformable web permitting it to be expanded radially outwardly for anchoring the bolt in a borehole.

I claim: 
     
       1. An anchor bolt assembly arranged to be inserted into and anchored within a borehole and including an anchor bolt and an expansion sleeve mounted on said anchor bolt, said anchor bolt having a leading end first inserted into the borehole and an opposite trailing end, said anchor bolt comprises an axially extending cylindrically shaped body extending from the trailing end toward the leading end, an axially extending frusto-conical part extending from the leading end toward the trailing end with the maximum diameter of said frusto-conical part being substantially the same as the diameter of said cylindrically shaped body, said frusto-conical part tapering inwardly in the direction from the leading end toward the trailing end, an axially extending reduced diameter part extending from said cylindrically shaped body to said frusto-conical part and having a diameter substantially the same as the minimum diameter of said frusto-conical part, wherein the improvement comprises an axially extending expansion sleeve extending continuously around and arranged to be fitted onto said reduced diameter part with the axis of said expansion sleeve extending in the direction of the axis of said anchor bolt, said sleeve having at least one web extending for a part of the circumferential direction of said sleeve and in the axial direction of said sleeve for the full length thereof and said web being deformable relative to the remainder of said sleeve, said web having a wall thickness in the radial direction of said sleeve considerably less than the corresponding wall thickness of said sleeve, said expansion sleeve being deformable from a first condition to a second condition with said expansion sleeve in the first condition having a cylindrically shaped outside surface and a minimum inside diameter at least equal to the maximum diameter of said frusto-conical part and in the second condition said expansion sleeve being deformed in the region of said web so that the inside surface thereof moves inwardly whereby the inside surface in circumferentially spaced locations is in surface contact with the surface of said reduced diameter part and said webs being expandable from the second condition for securing said anchor bolt within a borehole. 
     
     
       2. An anchor bolt assembly, as set forth in claim 1, wherein the outside surface of said expansion sleeve is grooved in the axial direction with the wall thickness of each said web being defined between the bottom surface of the groove and the inside surface of the said expansion sleeve. 
     
     
       3. An anchor bolt assembly, as set forth in claim 1 or 2, wherein each said web has a wall thickness in the range of 0.2 to 0.4 times the wall thickness of the sleeve between said webs. 
     
     
       4. An anchor bolt assembly, as set forth in claim 3, wherein the circumferential dimension of each said web is in the range of 2 to 4 times the wall thickness of said sleeve between said webs. 
     
     
       5. An anchor bolt assembly, as set forth in claim 4, wherein three angularly spaced webs are formed in said expansion sleeve. 
     
     
       6. An anchor bolt assembly, as set forth in claim 5, wherein the inside surface of said expansion sleeve has a circular cylindrical shape in the first condition. 
     
     
       7. An anchor bolt assembly, as set forth in claim 6, wherein the inside surface of said sleeve has a generally polygonally shaped configuration in the second condition thereof. 
     
     
       8. An anchor bolt assembly, as set forth in claim 7, wherein each said web is deformed into a generally U-shaped configuration in the second condition of said expansion sleeve. 
     
     
       9. An anchor bolt assembly, as set forth in claim 8, wherein the outside surfaces of said expansion sleeve adjacent said webs project outwardly from the outside diameter of said cylindrically shaped body in the second condition of said expansion sleeve. 
     
     
       10. An anchor bolt assembly, as set forth in claim 9, wherein in the second condition the inside surface of said expansion sleeve is in contact with said reduced diameter part at locations spaced angularly from said webs.